Condenser tester



Nov. 14,1944. M. w. GAISER 7 2,362,691

CONDENSER TESTER Filed July 31, 1941 3 Sheets-Sheet 1 Nov. 14, 1944. M wGNSER 2,362,691

CONDENSER TESTER Filed July 31, 1941 5 Sheets-Sheet 2 Zhwentor 7 4%???zl az'sev M ZZZ I y I I (Ittomegs Patented Nov. 14, 1944 CONDENSERTESTER Martin W. Gaiser, Kokomo, Ind., assignor to General MotorsCorporation, Detroit, Mich., a corporation of Delaware Application July31, 1941, Serial No. 404,825

7 Claims.

This invention relates to testing means and more specifically to meansfor automatically applying aseries of tests to condensers to ascertainwether they are satisfactory for a particular usage. In the manufactureof devices in large means are arcuately spaced around the peripheryquantities, such as, for example, radio receivers, of the disc 6 and arecomposed of a plurality of it is of course necessary to make a finalcheck spaced bars l2 and I4. These bars l2 and ll of condensers beforethey are applied to the are positioned substantially radially of thedisc chassis in production and it is necessary at this but have L-shapedextensions which extend over time to apply several tests thereto. Thereare 10 the periphery of the disc, as best shown in Figure a number ofthese fixed condensers used in each 1, and are secured to the disc byhaving bolts unit and therefore it is almost essential to have such asl6 which go through e P mom? automatic machinery to test these in orderto bers l2 and I4 and are threaded into arcuate conmaintain a sufllcientspeed to keep up with protacts 20 or I9 in such a manner that one of theduction of the receivers. side bars [4 is connected to one arcuatecontact It is therefore an object of my invention to and the other sidemem '2 is nnected to provide means for fully automatically testing theother arcuate contact conductively, but the fixed ndens r two areinsulated from each other. In other It is a further object of myinvention to autowords, the alternate bolts are insulated from thematically apply a series of tests to such conbar which it is desired toisolate therefrom. densers. This is best shown in the upper right-handcor- It is a still further object of my invention to r f Figure 4 wheretwo bolts are shown directly automatically apply a series of tests tofixed conconnected to the Side a s I! and I4 and the enser nd h v th unti f t or faulty alternate two are shown with an insulating collarcondensers discharged at such point as they fall therearound- Thus w n acondenser is to pass the tests. dropped between the clamping portions,one ter- 1; is un further object of my invention to minal will beconnected to one arcuate contact provide means for automaticallycollecting the and the pp t terminal will be connected to satisfactorycondensers which have passed all the other affiliate n act. the t t atthe end of th t cycle, Through the upstanding edge of the member It is astill further object of my invention to is an axially extending hole 2 uh which provide automatic means for testing fixed cona P 24 Projects andt e d o S id p n there densers which may be adjusted to accommodate isrigidly Secured a clamping block e Opp a large variety of types ofcondensers. site end of the pin carying one end of a lever 28 w th theseand other object in view, the which extends between the two pins ofmembers bodiments of my invention will be best under- I2 and H for any ec mpi g assembly. Bestood by reference to the following specificationtween said level and the back face of the 1 and claims and theillustrations in the accomthere is Provided a Spring 30'which tendspanying drawings, in which: to keep the clampin block 26 against thefront Figure 1 is aside elevation of a device embodyface 0f the membersI! nd I4. Each of the ing my invention; clamping stations is identical,and, as before Figure 2 is a detailed section taken on line 2 2mentioned, t same are ed pe ipherally of Figure 1; about the disc. t

Figure 3 is a detailed sectional View taken on The frame 2 also carriesa plurality of spaced line 3.4 of Figure 4; rotatable wheels 32 and 33around which is driven Figure4isafront view of the machine embodyanendless belt 34 which carries a p ura it of ing my invention; and spacedcarrier members 36 which in this instance Figure 5 isva schematic wiringdiagram show; are best shown in detail in Figure 2 as being a ing theelectrical connections necessary for the bracket bent D at o h e d ndprovidin V- ma hi shaped notch in the center to accommodate a Referringow specifically t Figure 1, th r i fixed condenser. These are riveted bysmall shown a'supporting frame2upon which is ountrivets 38 to theendless belt 34 which carry on ed a driving motor 4, which, throughsuitable their lower ends small rotatable guide wheels 40 gearing, isconnected to a rotatable vertical disc to eep h b lt on th ivi Wheels-The B and also a spaced vertical shaft 8. The disc 6 Wheel 33 has oneend of the hub thereof of small is made of insulating material andcarries at regularly spaced intervals around the periphery thereof aseries of clamping means In to support the condensers to be tested.These clamping diameter, as shown at 42, which has the outer facebeveled and toothed to form a beveled gear 44 which cooperates with andis driven by the beveled gear 48 on the upper end of the shaft 8. Itwill thus be evident that as the motor 4 rotates, the disc 8 will berotated, and at the same time the shaft 8 will drive the endless feedingcarrier and the various carriers sswm deposit condensers to be tested atthe upper edge of the disc 8.

As each one of the clamping asemblies rotates to the uppermost position,the lever 28 thereof will engage a small vertical roller 48 mounted on athe frame which will depress it toward the left in Figure 1, thuscausing the pair of clamping jaws on the two members I4 and I2 of thatparticular assembly to move out and allow the terminals of thecondensers to be tested to go do n, between the movable jaw and thestationary portion, and as the disc 8 continues to rotate. thecompression springs 88 will'clamp the condenser tightly in place and atthe same time connect it electrically to the two arcuate contacts I8 and28. The spacing of the clamping. assemblies, I8

and of the carriers 88 is such that as each carrier 38 reaches aposition in which it discharges the condenser which it is carrying, apair of clamping jaws are in position to receive the condenser which isdischarged therefrom. Thus as the motor 4 continues to operate, a seriesof condensers will be transmitted by the continuous carrier and will beclamped in test positions about the periphery of the rotating insulateddisc 8.

The condensers will therefore be taken slowly around in an arcuate pathto different test positions and tested for various properties thereof.There are in this instance two tests which are made: the first for shortcircuit or leak, and the second to test as to whether the capacity fallswithin certain preset tolerance limits. At various positions in therotation of the test disc there are provided means for releasing thecondenser if it does not fulfill the requirements of that test, andthese are in the form of solenoids such as 88 or 52 as shown in Figure1, which, when energized. assume a positionwhich wil cause the lever 28of the assembly being tested to force out the clamping jaws 28 andrelease the condenser at the point. Thus, if the condenser is found tobe shorted or leaking, it will be released at one point, or if it fallsoutside of the capacity tolerances, will be discharged at another point.If it passes all of the required tests, it comes to a position where therelease bar 28 thereof engages a small roller 88 on the frame which issubstantially the same as'the roller 48, which roller depresses thelever 28 and causes the condenser to be discharged into a chute 88 forgood condensers.

- .This last discharge position'is shown in detail in Figure 3 and isthe position shown in dotted lines on Figure 4 at the lower right-handportion of the device. 4 Referring now particularly to Figure 5, thecircuit .diagram of the device, we find therein a Plug 88 to which isconnected a suitable source of alternating current. One side of thisplug is connected by line 82 to a transformer primary 84 and also to asecond transformer primary 88. In series with the first transformerprimary is a variable resistance 88, the opposite side of which isconnected to ground. The secondary of the transformer just mentioned issplit and forms two portions I8 and I2, both terminals of windings ofthe secondary I8 being connected to the cathode I4 of a rectifiertubeand the terminals of the second secondary winding I2 beingrespectively supply voltages of 200, 400, 600 or 800.

connected to anodes I8 and I8 of the same rectifier tube, the centerpoint of the secondary winding I2 being connected to ground.

The center point of the secondary I8 is connected by line 88 to a filter82 and thence by line 84 to a pair of voltage dividers 88 and 88 whichhave a plurality of contactors thereon to Of course these are onlyexemplary and any desired voltage may be applied by the adjustment onthe voltage, supply. The movable contact 88 of the voltage divider-'88is connected through a high resistance 82 to line 84 to a voltmeter 88and also to one contact 98 which is adapted to wipe over the arcuatecontact 28 of the particular clamping assembly in that test position atthe time. There is also provided a contact I88 which is connected toground and is adapted to wipe over the associated arcuate conductivecontact I8 of the assembly. The opposite side of the voltmeter 88 isalso connected to ground.

The said voltage divider 88 has its movable or adjustable contact I82connected to a high resistance I84 and through line I88 to a wipingcontacti III in a second test position. The associated wiper contact I88thereof is connected to line H2 and thus to a fuse I, the opposite sideof whichis connected to coil II8 of a very sensitive relay, the oppositeend of the coil being connected to ground and also to the movable relaymember II8 which cooperates with a stationary contact I28 connectedthrough line I22 to a power rela I24 which is connected through line I28to one side of the secondary I28 of the second transformer associatedwith line 82. Line I28 also extends to coil I88 of a timing relay, theopposite terminal of which is connected byline I82 to terminal I84adjacent the lower portion of the rotating disc. In close proximity toterminal I84 is a second stationary wiper terminal I88 which isconnected directly to ground.

The secondary I28 of the transformer just mentioned provides power to anamplifier through having the upper terminal of the secondary connectedthrough line I88 to plate I48 and having a tap thereon connected throughline I42 to the filament I44, the opposite side of which is connectedthrough line I48 to line I28 and thus to the lower end oi the secondaryI28. An indirectly heated pair of cathodes I48 and I88 are connectedtoground, the former being connected through condenser I52, also to theline I28. A second plate I54 of this amplifier tube is connected by lineI88 to a power relay I88, the opposite side of which is connected byline I88 to one of the contacts of the voltage divider 88. A negativebias resistance I82 is connected between line I28 and one of the controlgrids I84 of the tube. The second grid I88 is connected by line I88toline I88 just mentioned.

The energization of either of the power relays I24 or I88 will closetheir associated switches I88 and "8 to operate the ejection solenoids82 and 58. The initial actuation of either of these ejection solenoidscloses a micro-switch III or I12 to maintain the ejection circuit closeda suflicient length of time and prevent chattering. Both the contactsand is connected to ground through line I98. The actuating coil I92 ofthe meter has one end connected to line H2 and the opposite endconnected through line I94 to one D. C. terminal I96 of a rectifier I98which may as an example be of thebridge type. A second A. C. terminal288 of the rectifier I98 is connected by line 282 t a movable blade 284of a double-pole, double-throw knife switch, the other movable blade 288being connected by line 286 to main supply line 62.

A third D. C. rectifier contact 2 Ills connected by line 2I2 to the coilI92 anda fourth A. C. rectifier contact 2 I4 is connected to :fuse 2 I6and then to the secondary winding 2I8 of an impedance matching isolationtransformer by line 228. The opposite terminal of the winding 2I8 isconnected by line 222 to ground. A variable resistance 224 is connectedacross the winding 2I8 and is provided with a switch 226 so that it maybe placed in shunt to the transformer winding or out entirely, asdesired. The primary winding 228 of the impedance matchin transformerhas one terminal connected to ground and the opposite terminal connectedto one terminal of a voltage doubling transformer 238 by line 232. Theopposite terminal of the voltage doubling transformer is connected toground. The center tap 234 on the transformer 238 is connected by line236 to the movable member 248 of a voltage varying device 238, saiddevice 238 being connected by line 242 to a voltage regulator 244 whichis connected across the supply line.

The opposite side of the supply line is connected directly to the motor4 which is also connected to a stationary contact 246 of thedouble-pole, double-throw switch. A standard condenser 248 is connectedbetween another of the switchs terminals 258 and ground. 'A dischargingresistor 252 is connected between two terminals 254 and 256 adjacent thedrum.

It will thus be obvious from the previous discussion that there areseveral positions at which the electrodes clamping the condenser beingtested are connected to various portions of the test apparatus. When thedisc carrying a condenser to be tested has reached position'A, a.voltage is applied thereto of a desired value, dependin upon thecondenser to be tested, to charge said condenser. This charge thereforeremains on the condenser (if it is satisfactory) until the condenserreaches test point B at which point the charge upon the condenser ismeasured and if it falls outside of certain limits the ejector solenoidwill be energized and the condenser physically released from the clamps.If, on the other hand, it

' is satisfactory, it will proceed to test point C, at

which point it will be discharged through a load resistor. It thenproceeds to testing point D, at which point A. C. current is suppliedthereto to measure the capacity. If the capacity thereof falls betweenpreset high and low limits, it then passes on to a discharge point.

With this general discussion, therefore, let us trace through the actualoperation of the device. As previously mentioned, the condenser is fedinto the slots by the endless conveyor which meets each one of the testpositions on the rotating vehicle disc and the condenser is then rotatedabout a horizontal axis by the motor 4. When it reaches test position Ait is conductively secured between stationary contacts 98 and I88. Priorto this time the apparatus has been set to accommodate 2,362,691 of themeter m floats between the two stationary this particular type ofcondenser and the mov- 78 able arms 98 and I82 of the voltage dividerhave.

been set for the particular voltage upon which this condenser isdesigned-t0 operate. This voltparticular value, the amounts cited hereinbeing only exemplary of a satisfactory supply for a large number ofdifferent types of condensers. The voltage dividers have four adjustabletaps and in this instance are capable of supplying 288-400- 600 and 808volts, respectively, to the adjustable contact 88 or I82, as desired.The voltage applied .to .this movable member 98 then passes through anisolating resistor 92 and may be read on the voltmeter 96; It is alsoapplied to the terminal 88 which as before mentioned is adapted tocontact one terminal of the clamping member for the condenser to betested. The other terminal I88 is, as shown, connected to ground. Thuswhen the condenser reaches test point A a desired voltage of, let us say200 volts, is applied thereto.

The large disc continues to rotate and the condenser therefore isremoved from contact with the supply and during the length of timenecessary for the disc to berotated from point A to point B thecondenser should retain its charge. If there is a leak or short thereinthe charge will become smaller before the condenser has reached testpoint B. Test point B is supplied with power in exactly the same manneras test point A, only this time through the voltage divider 88, theamount being set by the position of the adjustable arm I82. This voltageas before is applied through an isolating resistor to prevent directshort circuit. This source of power is connected to stationary terminalI88 at test point B, the opposite terminal II8 :being connected througha fuse and operating coil II6 of a meter II8 to ground. If the condenseris satisfactory and has remained in its charged state, when it reachestest position B and has again applied thereto a voltage identical tothat already applied at point A there will be no appreciable flow ofcurrent and the switch II 8-I28 will remain open, as shown.

However, if the condenser is shorted or leaky, then there will be asubstantial flow of current from the voltage divider 88 through thecondenser and through operating coil II6 to ground. This will causeswitch II8I28 to close and this closure will operate a power relay I24through an obvious circuit from the secondar I28 to ground throughswitch Ila-I28. Closure of this power relay will in turn cause theswitch I68 to close which will energize the ejector relay 52 through thefollowing circuit: From supp y line I18, through switch I16, line II4,switch I68, solenoid 52 to ground. Upon very slight movement of theejector relay a holding circuit through microswitch III is set up,shunting the switch I68 so that the solenoid will remain in ejectingposition for a given time and will not chatter. This circuit is throughlines 258 to switch "I and then from there through line 268 to the endof the solenoid coil. This shunts switch I68.

There therefore only remains in the supply circuit the switch II6 whichis operated by a timing relay I38. This timing relay is not operateduntil the end of that portion of the test cycle and this occurs when thetwo contacts I34 and I38 ride oif the same contacting bar on the dial 8which is adjacent the contacts at that time. At this time the relay I isdeenergized and the switch I18 opened to bring any one of the operatedejector solenoids back to its deenergized position. It might be statedat ,this point that the arcuate distance between articles to be testedis sufficient to be greater than the distance between test positions Band D so that the solenoid 52 will always be deenergized upon theapproach of a new condenser to be tested.

If the condenser is not shorted, it passes test point B satisfactorily,the solenoid 52 is not operated to cause its ejection and arrives attest point C where it is directly shunted by a load resistor 252 whichallows the condenser to discharge slowly to prevent any damage. u

It then passes on to test point D and it will be noted that one side ofthe condenser is connected directly to ground through terminals I34, I38(which are together) and the other is connected to switch 204-208 whichis as before stated a double-pole, double-throw switch. When this switchis in its downward position the motor M is deenergized, which motor runsthe transporting means, and the opposite side 204 connects a standardscondenser 248 of the type to be tested to the testing equipment. Whenthe switch is in its uppermost position the motor is energized and alsothe condenser being tested is connected to this portion of the testequipment.

For this particular test a voltage regulator 244 is utilized to providea substantially constant voltage and to accommodate any change in linevoltage. A variable voltage device 238 is also utilized and by movingthe movable arm 240 any voltage from substantially zero to, in thisinstance 270 volts, may be supplied to the line 238. An autotransformer230 is used also to double the voltage supplied from the variablevoltage supply. These various parts are merely included so that thedevice will accommodate a large range of capacities in condensers to betested. If only one type were to be tested. it would not be necessary toutilize this equipment. The transformer 2I8- 228 is used as an isolatingand impedance matching transformer and here again the value may bealtered by having the shunting resistance 224 across the secondary 2I8,which adjustment is used as a micro-achustment on higher capacitycondensers.

The rectifier I88200--2I02I4 passes D. C. current in direct proportionto the capacity of the. condenser to the operating meter movement I82since the capacity determines the A. C. current flow through therectifier circuit and therefore the proportional D. C. component. Thiscoil I82 with its associated indicating needle is adjusted so that withthe normal current flow through the condenser the needle I88 will liebetween the two stationary contacts I82 or I84, the distance between thetwo being adjustable and being preset to cover the tolerance range ofthe condenser. The condenser 212 is utilized tofilter the D. C. currentto prevent chattering in the meter movement. With the standard condenser248 in place and switch 204, 208 down, variable volt age supply 238 andrheostat 224 are so adjusted that the contact for I88 on the meter I88is on mid-scale. The contacts I82 and I84 are set to the high and lowpercentage tolerance marks for this type of condenser, as beforementioned. The scale of this meter is calibrated at zero percent inmid-scale and from zero to plus 100% on one side and to minus 100% onthe other side.

- the A. C. series circuit of the rectifier.

Theswitch 204, 208 is then thrown up to place the condenser under test,which now lies at test point ,D in the circuit, by applying it directlyin If the condenser is outside its percentage tolerance or capacity, theD. C. current through coil I32 will be above or below the standard andcontactis made between movable arm I88 and, let us say, stationarycontact I84. This removes the voltage from the grid I84 of the amplifiertube, causing electron flow through the plate I54 of this tube, which inturn causes flow in the circuit containing the relay coil I58. Thetrigger action of the amplifier in this case gives a very sensitiveresponse. This causes switch. I10 to close, which energizes ejectorsolenoid 50 in exactly the same way and from the same source of supplyas ejector solenoid 52. Likewise, in this case the mechanlcal movementof the solenoid armature causes closure of a micro-switch I12,establishing a shunt circuit around the switch I10 to maintain thesolenoid 80 in its ejecting position until the timing elay I38 isdeenergized by the circuit being broken between points I34 and I38.

If the condenser is satisfactory, however, and the movable armature I88does not contact either I82 or I84, the ejector relay 50 is not operatedand the condenser passes on to be mechanically ejected by a cam 58 at apoint some distance after test point D. It will thus be obvious from anexamination of the above that the various tapped resistors andadjustable means make it possible to test a large number of diflerentvarieties of condensers and that once the mechanisms have been adjustedthat type or condenser may be tested with great rapidity, it only beingnecessary to feed the same to theconveyor belt and they then areautomatically brought through the test positions and ejected at theproper point.

I claim:

1. In a device for testing condensers, movable means for moving saidcondensers along a predetermined path past a series of test positions,

a source of adjustable regulated alternating curtacts to vary the biason the electronic meansand control the operation of the selective means.

2. In a device for testing condensers, movable means for moving saidcondensers alon a predetermined path past a series of test positions, asource of adjustable regulated alternating current connected to a testposition, a rectifier connected thereto, a balanced meter relayconnected to the rectifier whereby the A, C. current flow through acondenser is measured by the D. C. proportionate current tothe relay, apair of spaced contacts one on each side of the balanced relay arm andejection means controlled by either of said contacts to cause thecondenser to be removed from the moving means.

3. In a device for testing condensers, movable means for moving saidcondensers along a predetermined path past a series of test positions, asource of adjustable regulated alternating current connected to a testposition, a rectifier connected thereto, a balanced meter relayconnected to the rectifier whereby the A. C. current flow through acondenser is measured, a pair of spaced contacts one on each side of thebalanced relay arm, a multi-electrod amplifier tube normally biased toprevent flow therethrough, said biasing means being connected to thespaced contacts, ejection means to cause removal of a condenser from themovable means, another electrode of said amplifier connected to saidejection means and controlling the operation thereof whereby whencontact is made between the contacts and the relay arm the bias isremoved from the tube and the ejector is actuated.

4. In a device for testing condensers, movable means for moving saidcondensers along a predetermined path past a series of test positions, asource of adjustable regulated alternating current connected to a testposition, a rectifier connected thereto, a balanced meter relayconnected to the rectifier whereby the flow through the condenser ismeasured, a pair of spaced contacts on on each side or the balancedrelay arm, ejection means controlled by either of said contacts to causethe condenser to be removed from the moving means, and locking means tomaintain said ejection means in ejecting position until the end of thetest cycle.

5. In a device for testing condensers, movable means for moving saidcondensers along a predetermined path past a series of test positions, asource of adjustable regulated alternating current connected to a testposition, a rectifier connected thereto, a balanced meter relayconnected to the rectifier whereby the fiow through the condenser ismeasured, a pair of spaced contacts one on each side or the balancedrelay arm representing high and low tolerances, condenser meansconnected across the relay to prevent chatter thereof, and ejectionmeans controlled by said contacts to cause the condenser to be removedfrom the moving means.

trolled by said contacts to cause the condenser to be removed from themoving means, and locking means for the ejecting means to maintain thesame energized until the test position has been passed.

7. In a device for testing condensers, movable means for moving saidcondensers along a predetermined path past a series of test positions, asource of adjustable regulated alternating cur-- rent connected to atest position, a rectifier connected thereto, a balanced meter relayconnected to the rectifier whereby the fiow through the condenser ismeasured, a pair of spaced contacts one on each side 01' the balancedrelay arm representing high and low tolerances, a multi-electrodeamplifier tube normally biased to prevent flow therethrough, saidbiasing means being connected to the spaced contacts, ejection means tocause removal of a condenser from the movable means, another electrodeof said amplifier connected to said ejection means and controlling theoperation thereof whereby when contact is made between the contacts andthe relay arm the bias is removed from the tube and the elector isactuated, and locking means for the ejecting means to maintain the sameenergized until the test position has been entirely passed.

MARTIN W. GAISER.

